Automated parameter adjustment to compensate self adjusting transmit power and sensitivity level at the node b

ABSTRACT

A small base node such as a Home Base Node (HNB), or femto cell, may reduce its transmit power in order to prevent co-channel or adjacent channel interference, or to limit its coverage area. Once the power is set, the HNB signal to a served Home User Equipment (HUE) its transmit Common Pilot Channel (CPICH) transmit power for accurate path loss estimation. When this power is outside of the permissible range, the HNB adjusts other parameters (such as Random Access Channel (RACH) constant value) to compensate for the error in signaled CPICH power, and thus compensate in that process the error in determining path loss. Similarly, if the uplink sensitivity is adjusted, to prevent interference, parameters would also be adjusted and signaled to the HUE to reflect the link imbalance.

CLAIM OF PRIORITY UNDER 35 U.S.C. §119

The present Application for Patent claims priority to ProvisionalApplication No. 61/087,861 entitled “NODE B TRANSMIT POWER ADJUSTMENT”filed Aug. 11, 2008, and assigned to the assignee hereof and herebyexpressly incorporated by reference herein.

BACKGROUND

1. Field

The present disclosure relates generally to communication, and morespecifically signaling uplink transmit power to user equipment (UE) in awireless communication network.

2. Background

In third generation wireless mobile communication technology, theUniversal Mobile Telecommunication System (UMTS), also known as 3GSM(Third Generation Global System for Mobile Communications), is onecommunication protocol used for communications on a wireless network.One such type of wireless network is a UMTS Terrestrial Radio AccessNetwork (UTRAN) which typically includes base stations and controllersto form the UMTS wireless network. This wireless communications network,commonly referred to as a 3G (for Third Generation) network, can carrymany traffic types, from real-time circuit switched traffic to InternetProtocol (IP)-based packet switched traffic. The UTRAN allowsconnectivity between user equipment (UE), such as mobile phones orwireless communication devices, and to devices on other communicationnetworks.

Base stations typically include transmitters and receivers used tocommunicate directly with the UE, which may move freely around anetwork. A Radio Network Controller (RNC) governs communications on theUTRAN by controlling the operation of the base stations on the network.The RNC carries out radio resource management, some of the mobilitymanagement functions and is the point where encryption is done beforeuser data is sent to and from Mobile User Equipment (MUE).

Under UTRAN, the RNC can configure UEs operating within the network tooperate according to particular communication system parameters. (See3GPP Technical Specification 25.331) For example, during initiation orreconfiguration, a Radio Bearer Setup message may be sent by the RNC toa UE that configures a transmitter and/or receiver in the UE to operateaccording to parameters (e.g., combination of transmitted and receiveddata blocks, mapping between channels and services, etc.) sent in theRadio Bearer Setup message. The UE may receive a new Radio Bearer Setupmessage when it is started or when it awakes from a standby mode. Forexample, a UE may be configured to conserve power by switching itstransmitter and/or receiver On and Off, causing it to have to reset itstransmitter and/or receiver parameters.

In some scenarios, a RNC, such as a base station or base node, wishes touse a transmit power that is outside the range that can be signaled in acertain release of the specification. Later releases of thespecifications can expand this range, but the older UEs or MobileStations (MSs) that are in the field will not understand these newfields. This signaled power is used at the UE mainly for path lossestimation.

SUMMARY

The following presents a simplified summary in order to provide a basicunderstanding of some aspects of the disclosed aspects. This summary isnot an extensive overview and is intended to neither identify key orcritical elements nor delineate the scope of such aspects. Its purposeis to present some concepts of the described features in a simplifiedform as a prelude to the more detailed description that is presentedlater.

In one aspect, a method is provided for signaling on a downlink adjustedparameters to accurately set a transmit power level for an uplink byemploying a processor executing computer executable instructions storedon a computer readable storage medium to implement following acts: Atarget transmit power level that is desired for user equipment that isoutside of a defined range for a power command by an offset value isdetermined. A power command is transmitted at a value within the definedrange that is closest to the target transmit power level. A mitigationsignal is transmitted based upon the offset value. An uplink channel isreceived at the target transmit power level, wherein the user equipmentadjusts transmit power from the power command according to themitigation signal.

In another aspect, a computer program product is provided for signalingon a downlink adjusted parameters to accurately set a transmit powerlevel for an uplink. At least one computer readable storage mediumstores computer executable instructions that, when executed by at leastone processor, implement components: A first set of codes determines atarget transmit power level that is desired for user equipment that isoutside of a defined range for a power command by an offset value. Asecond set of codes transmits a power command at a value within thedefined range that is closest to the target transmit power level. Athird set of codes transmits a mitigation signal based upon the offsetvalue. A fourth set of codes receives an uplink channel at the targettransmit power level, wherein the user equipment adjusts transmit powerfrom the power command according to the mitigation signal.

In an additional aspect, an apparatus is provided for signaling on adownlink adjusted parameters to accurately set a transmit power levelfor an uplink. At least one computer readable storage medium storescomputer executable instructions that, when executed by at least oneprocessor, implement components: Means are provided for determining atarget transmit power level that is desired for user equipment that isoutside of a defined range for a power command by an offset value. Meansare provided for transmitting a power command at a value within thedefined range that is closest to the target transmit power level. Meansare provided for transmitting a mitigation signal based upon the offsetvalue. Means are provided for receiving an uplink channel at the targettransmit power level, wherein the user equipment adjusts transmit powerfrom the power command according to the mitigation signal.

In another additional aspect, an apparatus is provided for signaling ona downlink adjusted parameters to accurately set a transmit power levelfor an uplink. A computing platform determines a target transmit powerlevel that is desired for user equipment that is outside of definedrange for a power command by an offset value. A transmitter transmits apower command at a value within the defined range that is closest to thetarget transmit power level and for transmitting a mitigation signalbased upon the offset value. A receiver receives an uplink channel atthe target transmit power level, wherein the user equipment adjuststransmit power from the power command according to the mitigationsignal.

In a further aspect, a method employs a processor executing computerexecutable instructions stored on a computer readable storage medium toimplement following acts: An actual transmit power is determined thatresults in common pilot channel power outside of a valid range. A valueis transmitted on a downlink for common pilot channel power at a lowestvalid value. A constant value is transmitted according to the actualtransmit power. A random access channel preamble is received from userequipment according to an actual path loss based upon the value forcommon pilot channel power and the constant value.

In yet one aspect, a computer program product comprises at least onecomputer readable storage medium storing computer executableinstructions that, when executed by at least one processor, implementcomponents: A first set of codes determines that an actual transmitpower that results in common pilot channel power outside of a validrange. A second set of codes transmits on a downlink a value for commonpilot channel power at a lowest valid value. A third set of codestransmits a constant value according to the actual transmit power. Afourth set of codes receives a random access channel preamble from userequipment according to an actual path loss based upon the value forcommon pilot channel power and the constant value.

In yet another aspect, an apparatus comprises at least one computerreadable storage medium for storing computer executable instructionsthat, when executed by at least one processor, implement components:Means are provided for determining that an actual transmit power thatresults in common pilot channel power outside of a valid range. Meansare provided for transmitting on a downlink a value for common pilotchannel power at a lowest valid value. Means are provided fortransmitting a constant value according to the actual transmit power.Means are provided for receiving a random access channel preamble fromuser equipment according to an actual path loss based upon the value forcommon pilot channel power and the constant value.

In yet an additional aspect, an apparatus comprises a computing platformfor determining that an actual transmit power that results in commonpilot channel power outside of a valid range. A transmitter transmits ona downlink a value for common pilot channel power at a lowest validvalue and transmits a constant value according to the actual transmitpower. A receiver receives a random access channel preamble from userequipment according to an actual path loss based upon the value forcommon pilot channel power and the constant value.

In yet another additional aspect, a method employs a processor executingcomputer executable instructions stored on a computer readable storagemedium to implement the following acts: Interference is mitigated byreducing uplink receiving to an actual sensitivity. A parameter isadjusted to force user equipment to transmit a random access channelpreamble at a value corresponding to the actual sensitivity. Theadjusted parameter is transmitted to the user equipment. The randomaccess channel preamble is received.

In yet a further aspect, a computer program product comprises at leastone computer readable storage medium for storing computer executableinstructions that, when executed by at least one processor, implementcomponents: A first set of codes mitigates interference by reducinguplink receiving to an actual sensitivity. A second set of codes adjustsa parameter to force user equipment to transmit a random access channelpreamble at a value corresponding to the actual sensitivity. A third setof codes transmits the adjusted parameters to the user equipment. Afourth set of codes receives the random access channel preamble.

In another further aspect, an apparatus comprises at least one computerreadable storage medium storing computer executable instructions that,when executed by at least one processor, implement components: Means areprovided for mitigating interference by reducing uplink receiving to anactual sensitivity. Means are provided for adjusting a parameter toforce user equipment to transmit a random access channel preamble at avalue corresponding to the actual sensitivity. Means are provided fortransmitting the adjusted parameters to the user equipment. Means areprovided for receiving the random access channel preamble.

In an additional further aspect, an apparatus comprises a computingplatform for mitigating interference by reducing uplink receiving to anactual sensitivity and for adjusting a parameter to force user equipmentto transmit a random access channel preamble at a value corresponding tothe actual sensitivity. A transmitter transmits the adjusted parametersto the user equipment. A receiver receives the random access channelpreamble.

To the accomplishment of the foregoing and related ends, one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative aspectsand are indicative of but a few of the various ways in which theprinciples of the aspects may be employed. Other advantages and novelfeatures will become apparent from the following detailed descriptionwhen considered in conjunction with the drawings and the disclosedaspects are intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

FIG. 1 illustrates a block diagram of a heterogeneous communicationnetwork wherein a Home Base Node (HNB) can signal an out-of-rangetransmit power command on a downlink for a Home User Equipment (HUE) touse on an uplink.

FIG. 2 illustrates a flow diagram for a methodology or sequence ofoperations for signaling transmit power outside of a defined validrange.

FIG. 3 illustrates a diagram of a wireless communication systemcomprising macro cells, femto cells and pico cells.

FIG. 4 illustrates a diagram of a communication system where one or morefemto nodes are deployed within a network environment.

FIG. 5 illustrates a diagram of a coverage map where several trackingareas, routing areas or location areas are defined.

FIG. 6 illustrates a diagram of a multiple access wireless communicationsystem.

FIG. 7 depicts a diagram of an apartment block in a dense-urban model.

FIG. 8 depicts a graphical plot of distribution of path loss (PL) from aplurality of mobile user equipment (MUEs) to the nearest Home Base Node(HNB) for a dense-urban model.

FIG. 9 illustrates a methodology or sequence of operations for an idlecell reselection procedure for determining whether a HUE is camped onits HNB or on a Mobile Base Node (MNB) or whether it is moved to anothercarrier.

FIG. 10 illustrates a methodology or sequence of operations for HNBtransmit power calibration.

FIG. 11 illustrates a graphical plot of a Home Base Node (HNB) transmitpower Cumulative Density Function (CDF) for a dense-urban scenario withminimum power Pmin=0 dBm and maximum power Pmax=20 dBm.

FIG. 12 illustrates a graphical plot of a transmit power CDF for adense-urban scenario with Pmin=−10 dBm and Pmax=20 dBm.

FIG. 13 depicts a block diagram of a logical grouping of electricalcomponents for signaling transmit power outside of a defined range.

FIG. 14 depicts a block diagram of an apparatus having means forsignaling transmit power outside of a defined range.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that the variousaspects may be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to facilitate describing these aspects.

In FIG. 1, in a heterogeneous communication system 100, a small basenode (e.g., Home Base Node (HNB), femtocell, closed subscription cell,etc.) 102, depicted as HNB, serves user equipment (UE) 104, depicted asHome User Equipment (HUE). For instance, the HNB 102 can be placedwithin a building 106 to extend coverage area of or to provide anadvantageous billing alternative over one of a plurality of Macro BaseNodes (MNBs) 108 a, 108 b.

Advantageously, the HNB 102 has a reduced Transmit (Tx) power component110 that seeks to determine a sufficient Transmit (Tx) power to avoidinterference to other nodes or to terminals while providing sufficientservice to a Mobile User Equipment MUE 112 a. For instance, the MNB 108a can be serving the MUE 112 a that is co-channel with the HNB 102. TheHNB 102 can advantageously reduce its Tx power to maintain a CommonPilot Channel (CPICH) Ec/No (energy per chip to interference powerdensity) of −18 dB for the MUE 112 a that is located X1 dB away from theHNB 102 as a first constraint depicted at 114.

Alternatively or in addition, the MNB 108 b can be serving MUE 112 bthat is served on an adjacent channel with the HNB 102. The HNB 102 canreduce its CPICH Tx power to avoid adjacent channel interference for theMUE 112 b that is located X2 away from the HNB 102 to prevent adjacentco-channel interference as depicted at 116.

Alternatively or in addition, to make sure that the HNB 102 is notcausing unnecessary interference to others (e.g., nodes or UserEquipment (UE)) 118, the HNB 102 can enforce a cap on CPICH Ec/No of −15dB as reported as depicted at 120 by the HUE 104 that is located X3 dBaway from the HNB 102.

In particular, the HNB 102 signals CPICH Transmit (Tx) power to the HUE104 by Radio Resource Control (RRC) and is used by the HUE 104 toestimate the path loss to the HNB 102. The estimated path loss is usedby the HUE 104 for determining the its initial Tx power for RandomAccess Channel (RACH):

Preamble_Initial_Power=Primary CPICH Tx power−CPICH_(—) RSCP+ULinterference+Constant Value

Currently, the lowest CPICH power level that can be signaled to the UEis −10 dBm as specified in 3GPP TS 25.331 v8.3.0, “Radio ResourceControl (RRC); Protocol specification”. When the Node B/HNB CPICH Txpower is below −10 dBm, the estimated path loss by the UE (i.e., PrimaryCPICH Tx power−CPICH_RSCP) will be higher than the actual path loss.This will result in a higher Tx power by the UE than necessary. Theincrease in the UE Tx power will expedite the access but at same timecauses unnecessary interference for the macro uplink.

In an exemplary aspect, currently, a new base station class for ThirdGeneration (3G) Home Base Node (HNB) is being defined. One of theobjectives is to update the radio requirements in TS 25.104 for HNBs.Although the minimum HNB transmit power is not part of thespecifications, the lower limit should be set appropriately to limit thecoverage hole created for a macrocell downlink. In the disclosedinnovation, the total HNB Transmit (Tx) power may need to go lower than0 dBm, which will result in a Common Pilot CHannel (CPICH) power levelbelow −10 dBm, assuming CPICH Ec/Ior=−10 dB, which is the minimum levelthat can currently be signaled to the UE. This could potentially resultin a mismatch between the signal CPICH Tx power and the actual powerlevel, which would increase Home User Equipment (HUE) open-loop Tx powerlevel for Random Access Channel (RACH). However, the mismatchadvantageously can be compensated by adjusting the Constant Valueparameter for RACH.

Thus, the Macro Base Nodes (MNBs)/HNB can use the Constant Valueparameter or the Uplink (UL) interference parameter to compensate forthe mismatch between the actual CPICH Tx power level and the onesignaled to the UE. The MNB/HNB will advertise the lowest possible valuein this case. The allowed range for the Constant Value parameter isspecified as [−35 dB . . . −10 dB]. The Constant Value signaled to theUE can be made lower than the desired target to offset the increase inthe estimated Path Loss (PL) resulted from the mismatch in CPICH Txpower. The same mechanism can be applied to the upper limit using theUplink (UL) interference parameter.

In another aspect, when path loss is the selected reporting quantity,adjustments can be provided when a defined range for path loss isinsufficient to convey an actual value. In this instance, mitigation canbe achieved by using Cell Individual Offset (CIO).

In an additional aspect, an HNB can adjust its receive sensitivity suchthat a desired uplink transmit power level for UE is outside of a rangethat can be directly commanded. For instance, if the HNB decreases itssensitivity, such as to mitigate interference, the UE can transmit attoo low of a power level to reach the HNB. Thus, the HNB indirectlycommands with a mitigating signal. In particular, in order to preventthe HUE from transmitting at too low of a power to reach the HNB, theHNB needs to indirectly signal its sensitivity using either the constantvalue or the uplink interference value.

In another aspect, when path loss is the selected reporting quantity,adjustments also need to be considered. In this instance, theadjustments can be done using Cell Individual Offset (CIO).

In a further aspect, the HNB adjusts its receive sensitivity for anuplink, which can create a similar problem in conveying settings to aserved HUE. With the reduced sensitivity, the HUE can transmit at toolow a transmit power in order to reach the HNB. Thus, the HNB needs toindirectly signal its sensitivity, using either constant value or the ULinterference value.

The HNB 102 can contain a computing platform 140 that executesinstructions locally or remotely stored in computer-readable storagemedia by at least one processor for performing the foregoing computingand control steps. The HNB 102 can further contain or have access to atleast one receiver (RX) 142 for receiving an uplink from the HUE 104.The HNB 102 can further contain or have access to at least onetransmitter (Tx) 144 for transmitting a downlink to the HUE 104.

In FIG. 2, a methodology or sequence of operations 200 is provided forsignaling transmit power below a defined valid range, in particular foran HNB to signal on a downlink to an HUE a transmit power level for anuplink in a closed subscriber system. The HNB determines a targettransmit power level that is desired for the HUE that is outside of adefined range for a power command by an offset value (block 204). TheHNB transmits a power command to the HUE at a value within the definedrange that is closest to the target transmit power level (block 206).The HNB transmits a mitigation signal to the HUE based upon the offsetvalue (block 208). The HNB receives an uplink channel at the targettransmit power level (block 210), wherein the HUE adjusts transmit powerfrom the power command according to the mitigation signal.

In one aspect, the HNB determines that an actual transmit power resultsin Common Pilot Channel (CPICH) power outside of a valid range (block212). The HNB transmits on a downlink a value for CPICH power at alowest valid value (block 214). The HNB transmits a constant valueaccording to the actual transmit power (block 216). The HNB receives aRandom Access Channel (RACH) preamble from HUE according to an actualpath loss based upon the value for CPICH power and the constant value(block 218). The HNB can further transmit a value for Cell IndividualOffset (CIO) to set handover boundaries based upon the actual path loss(block 220).

In another aspect, the HNB mitigates interference by reducing uplinkreceiving to an actual sensitivity (block 222). The HNB adjusts aparameter (e.g., uplink interference, constant values, etc.) to forcethe HUE to transmit RACH preamble at a value corresponding to the actualsensitivity (block 224). The HNB transmits the adjusted parameter to theHUE (block 226). The HNB receives the random access channel preamble(block 228).

Throughout this disclosure, for clarity an assumption is made forco-channel deployment where HUEs and MUEs share the same carrier. Aclosed subscriber group is assumed throughout. However, it should beappreciated with the benefit of the present disclosure that aspectsconsistent with the present innovation can include exceptions to theseassumptions and those that follow. In one aspect, a UE is deemed unableto acquire the pilot if the Common Pilot Channel (CPICH) Ec/No (energyper chip to interference power density) is below an acquisition timevalue (Tacq). For this analysis, Tacq=−20 dB is used. In addition, theMacro Base Nodes (MNBs) are assumed to transmit at 50% of the full power(i.e., 40 dBm). The CPICH Ec/Ior for MNBs and HNBs are set to −10 dB(i.e., 33 dBm).

In some aspects the teachings herein may be employed in a network thatincludes macro scale coverage (e.g., a large area cellular network suchas a 3G networks, typically referred to as a macro cell network) andsmaller scale coverage (e.g., a residence-based or building-basednetwork environment). As UE moves through such a network, UE may beserved in certain locations by Node Bs that provide macro coverage whileUE may be served at other locations by Node Bs that provide smallerscale coverage. In some aspects, the smaller coverage nodes may be usedto provide incremental capacity growth, in-building coverage, anddifferent services (e.g., for a more robust user experience). In thediscussion herein, a node that provides coverage over a relatively largearea may be referred to as a macro node. A node that provides coverageover a relatively small area (e.g., a residence) may be referred to as afemto node. A node that provides coverage over an area that is smallerthan a macro area and larger than a femto area may be referred to as apico node (e.g., providing coverage within a commercial building).

A cell associated with a macro node, a femto node, or a pico node may bereferred to as a macro cell, a femto cell, or a pico cell, respectively.In some implementations, each cell may be further associated with (e.g.,divided into) one or more sectors.

In various applications, other terminology may be used to reference amacro node, a femto node, or a pico node. For example, a macro node maybe configured or referred to as a Node B, base station, access point,eNodeB, macro cell, and so on. Also, a femto node may be configured orreferred to as a Home NodeB, Home eNodeB, access point base station,femto cell, and so on.

FIG. 3 illustrates a wireless communication system 300, configured tosupport a number of users, in which the teachings herein may beimplemented. The system 300 provides communication for multiple cells302, such as, for example, macro cells 302 a-302 g, with each cell beingserviced by a corresponding base node 304 (e.g., base nodes 304 a-304g). As shown in FIG. 3, UEs 306 (e.g., UEs 306 a-306 l) may be dispersedat various locations throughout the system over time. Each UE 306 maycommunicate with one or more base nodes 304 on a forward link (“FL”)and/or a reverse link (“RL) at a given moment, depending upon whether UE306 is active and whether it is in soft handoff, for example. Thewireless communication system 300 may provide service over a largegeographic region. For example, macro cells 302 a-302 g may cover a fewblocks in a neighborhood.

FIG. 4 illustrates an exemplary communication system 400 where one ormore femto nodes are deployed within a network environment.Specifically, the system 400 includes multiple femto nodes, depicted asHome Base Nodes (HNBs) 402 a and 402 b, installed in a relatively smallscale network environment (e.g., in one or more user residences 404).Each femto node 402 a-402 b may be coupled to a wide area network 406(e.g., the Internet) and a mobile operator core network 408 via a DSLrouter, a cable modem, a wireless link, or other connectivity means (notshown). As will be discussed below, each femto node 402 a-402 b may beconfigured to serve associated access terminals or user equipment (UE)410 a and, optionally, alien access UEs 410 b (e.g., not a subscriber toa closed subscriber group). In other words, access to femto nodes 402a-402 b may be restricted whereby a given UE 410 a-410 b may be servedby a set of designated (e.g., home) femto node(s) 402 a-402 b but maynot be served by any non-designated femto nodes 402 a-402 b (e.g., aneighbor's femto node 402 a-402 b).

The owner of a femto node 410 may subscribe to mobile service, such as,for example, 3G mobile service, offered through the mobile operator corenetwork 408. In addition, an access terminal or UE 410 a-410 b may becapable of operating both in macro environments and in smaller scale(e.g., residential) network environments. In other words, depending onthe current location of the UE 410 a-410 b, the access terminal 410a-410 b may be served by an access node or macro base node 412 of themacro cell mobile network 408 or by any one of a set of femto nodes 410(e.g., the femto nodes 402 a-402 b that reside within a correspondinguser residence 404). For example, when a subscriber is outside his home,he is served by a standard macro access node (e.g., node 412) and whenthe subscriber is at home, he is served by a femto node (e.g., node 402a-402 b). Here, it should be appreciated that a femto node 402 a-402 bmay be backward compatible with existing access terminals or UEs 410a-410 b.

A femto node 402 a-402 b may be deployed on a single frequency or, inthe alternative, on multiple frequencies. Depending on the particularconfiguration, the single frequency or one or more of the multiplefrequencies may overlap with one or more frequencies used by a macronode (e.g., node 412).

In some aspects, an access terminal or UE 410 a-410 b may be configuredto connect to a preferred femto node (e.g., the home femto node of theaccess terminal or UE 410 a-410 b) whenever such connectivity ispossible. For example, whenever the access terminal or UE 410 a-410 b iswithin the user's residence 404, it may be desired that the accessterminal or UE 410 a-410 b communicate only with the home femto node 402a-402 b.

In some aspects, if the access terminal or UE 410 a-410 b operateswithin the macro cellular network 408 but is not residing on its mostpreferred network (e.g., as defined in a preferred roaming list), theaccess terminal or UE 410 a-410 b may continue to search for the mostpreferred network (e.g., the preferred femto node 402 a-402 b) using aBetter System Reselection (“BSR”), which may involve a periodic scanningof available systems to determine whether better systems are currentlyavailable, and subsequent efforts to associate with such preferredsystems. With the acquisition entry, the access terminal or UE 410 a-410b may limit the search for specific band and channel. For example, thesearch for the most preferred system may be repeated periodically. Upondiscovery of a preferred femto node 402 a-402 b, the access terminal 410a-410 b selects the femto node 402 a-402 b for camping within itscoverage area.

A femto node may be restricted in some aspects. For example, a givenfemto node may only provide certain services to certain accessterminals. In deployments with so-called restricted (or closed)association, a given access terminal may only be served by the macrocell mobile network and a defined set of femto nodes (e.g., the femtonodes 402 a-402 b that reside within the corresponding user residence404). In some implementations, a node may be restricted to not provide,for at least one node, at least one of: signaling, data access,registration, paging, or service.

In some aspects, a restricted femto node (which may also be referred toas a Closed Subscriber Group Home NodeB) is one that provides service toa restricted provisioned set of access terminals. This set may betemporarily or permanently extended as necessary. In some aspects, aClosed Subscriber Group (“CSG”) may be defined as the set of accessnodes (e.g., femto nodes) that share a common access control list ofaccess terminals. A channel on which all femto nodes (or all restrictedfemto nodes) in a region operate may be referred to as a femto channel.

Various relationships may thus exist between a given femto node and agiven access terminal or user equipment. For example, from theperspective of an access terminal, an open femto node may refer to afemto node with no restricted association. A restricted femto node mayrefer to a femto node that is restricted in some manner (e.g.,restricted for association and/or registration). A home femto node mayrefer to a femto node on which the access terminal is authorized toaccess and operate on. A guest femto node may refer to a femto node onwhich an access terminal is temporarily authorized to access or operateon. An alien femto node may refer to a femto node on which the accessterminal is not authorized to access or operate on, except for perhapsemergency situations (e.g., 911 calls).

From a restricted femto node perspective, a home access terminal mayrefer to an access terminal that authorized to access the restrictedfemto node. A guest access terminal may refer to an access terminal withtemporary access to the restricted femto node. An alien access terminalmay refer to an access terminal that does not have permission to accessthe restricted femto node, except for perhaps emergency situations, forexample, such as 911 calls (e.g., an access terminal that does not havethe credentials or permission to register with the restricted femtonode).

For convenience, the disclosure herein describes various functionalityin the context of a femto node. It should be appreciated, however, thata pico node may provide the same or similar functionality for a largercoverage area. For example, a pico node may be restricted, a home piconode may be defined for a given access terminal, and so on.

A wireless multiple-access communication system may simultaneouslysupport communication for multiple wireless access terminals. Asmentioned above, each terminal may communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link may be established via a single-in-single-out system,a multiple-in-multiple-out (“MIMO”) system, or some other type ofsystem.

FIG. 5 illustrates an example of a coverage map 500 where severaltracking areas 502 (or routing areas or location areas) are defined,each of which includes several macro coverage areas 504. Here, areas ofcoverage associated with tracking areas 502 a, 502 b, and 502 c aredelineated by the wide lines and the macro coverage areas 504 arerepresented by the hexagons. The tracking areas 502 also include femtocoverage areas 506. In this example, each of the femto coverage areas506 (e.g., femto coverage area 506c) is depicted within a macro coveragearea 504 (e.g., macro coverage area 504 b). It should be appreciated,however, that a femto coverage area 506 may not lie entirely within amacro coverage area 504. In practice, a large number of femto coverageareas 506 may be defined with a given tracking area 502 or macrocoverage area 504. Also, one or more pico coverage areas (not shown) maybe defined within a given tracking area 502 or macro coverage area 504.

In particular, a wireless multiple-access communication system maysimultaneously support communication for multiple wireless UEs. Asmentioned above, each terminal may communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link may be established via a single-in-single-out system,a multiple-in-multiple-out (“MIMO”) system, or some other type ofsystem. It should be appreciated that the present innovation is notlimited to use in a MIMO system described herein as an exemplaryimplementation.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, where N_(S)≦min{N_(T), N_(R)}. Each of the N_(S) independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (“TDD”) and frequencydivision duplex (“FDD”). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

The teachings herein may be incorporated into a node (e.g., a device)employing various components for communicating with at least one othernode. FIG. 6 depicts several sample components that may be employed tofacilitate communication between nodes. Specifically, FIG. 6 illustratesa wireless device 610 (e.g., an access point) and a wireless device 650(e.g., an access terminal) of a MIMO system 600. At the device 610,traffic data for a number of data streams is provided from a data source612 to a transmit (“TX”) data processor 614.

In some aspects, each data stream is transmitted over a respectivetransmit antenna. The TX data processor 614 formats, codes, andinterleaves the traffic data for each data stream based on a particularcoding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by a processor 630. A data memory 632 may storeprogram code, data, and other information used by the processor 630 orother components of the device 610.

The modulation symbols for all data streams are then provided to a TXMIMO processor 620, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 620 then provides N_(T)modulation symbol streams to N_(T) transceivers (“XCVR”) 622 a through622 t that each has a transmitter (TMTR) and receiver (RCVR). In someaspects, the TX MIMO processor 620 applies beam-forming weights to thesymbols of the data streams and to the antenna from which the symbol isbeing transmitted.

Each transceiver 622 a-622 t receives and processes a respective symbolstream to provide one or more analog signals, and further conditions(e.g., amplifies, filters, and upconverts) the analog signals to providea modulated signal suitable for transmission over the MIMO channel.N_(T) modulated signals from transceivers 622 a through 622 t are thentransmitted from N_(T) antennas 624 a through 624 t, respectively.

At the device 650, the transmitted modulated signals are received byN_(R) antennas 652 a through 652 r and the received signal from eachantenna 652 a-652 r is provided to a respective transceiver (“XCVR”) 654a through 654 r. Each transceiver 654 a-654 r conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (“RX”) data processor 660 then receives and processes theN_(R) received symbol streams from N_(R) transceivers 654 a-654 r basedon a particular receiver processing technique to provide N_(T)“detected” symbol streams. The RX data processor 660 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. The processing by the RX dataprocessor 660 is complementary to that performed by the TX MIMOprocessor 620 and the TX data processor 614 at the device 610.

A processor 670 periodically determines which pre-coding matrix to use.The processor 670 formulates a reverse link message comprising a matrixindex portion and a rank value portion. A data memory 672 may storeprogram code, data, and other information used by the processor 670 orother components of the device 650.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 638, whichalso receives traffic data for a number of data streams from a datasource 636, modulated by a modulator 680, conditioned by thetransceivers 654 a through 654 r, and transmitted back to the device610.

At the device 610, the modulated signals from the device 650 arereceived by the antennas 624 a-624 t, conditioned by the transceivers622 a-622 t, demodulated by a demodulator (“DEMOD”) 640, and processedby a RX data processor 642 to extract the reverse link messagetransmitted by the device 650. The processor 630 then determines whichpre-coding matrix to use for determining the beam-forming weights thenprocesses the extracted message.

FIG. 6 also illustrates that the communication components may includeone or more components that perform interference control operations. Forexample, an interference (“INTER.”) control component 690 may cooperatewith the processor 630 and/or other components of the device 610 tosend/receive signals to/from another device (e.g., device 650).Similarly, an interference control component 692 may cooperate with theprocessor 670 and/or other components of the device 650 to send/receivesignals to/from another device (e.g., device 610). It should beappreciated that for each device 610 and 650 the functionality of two ormore of the described components may be provided by a single component.For example, a single processing component may provide the functionalityof the interference control component 690 and the processor 630 and asingle processing component may provide the functionality of theinterference control component 692 and the processor 670.

In FIG. 7, consider a scenario with simulation assumptions thatillustrates aspects of the disclosed innovation. In this disclosure, adense-urban model 700 corresponds to densely-populated areas where thereare multi-floor apartment buildings 702 a, 702 b with smaller sizeapartment units 704. The description of the dense-urban model is asfollows.

In the dense-urban model 700, blocks of apartments are dropped into thethree center cells of a macro cell layout with Inter-Site Distance (ISD)of 1 km. Each block is 50 m×50 m and consists of two buildings (northand south) 702 a, 702 b and a horizontal street 706 between them asshown in FIG. 7. The width of the street is 10 meters. Each building hasK floors. K is chosen randomly between 2 and 6. In each floor, there are10 apartment units in two rows of five. Each apartment is 10 m×10 m(i.e., approximately 1076 square feet) and has a one-meter-wide balcony.The minimum separation between two adjacent blocks is 10 m. Theprobability that a Home User Equipment (HUE) (e.g., femto cell) is inthe balcony is assumed to be 10%. Two thousand (2000) apartment unitsare dropped in each cell which corresponds to a 6928 households persquare kilometer. This represents a dense-urban area. Taking intoaccount various factors such as wireless penetration (80%), operatorpenetration (30%) and Home Base Node (HNB) penetration (20%), a 4.8% HNBpenetration is assumed which means 96 of the 2000 apartments in eachcell have a HNB installed from the same operator. Out of these, 24 HNBsare simultaneously active (have a HUE in connected mode). If a HNB isactive, it will transmit at full power; otherwise it will transmit onlythe pilot and overhead channels.

A plurality of Mobile User Equipment (MUEs) are also dropped randomlyinto the three center cells of the 57-cell macro layout such that 30% ofthe MUEs are indoor. In addition, a minimum path loss of 38 dB isenforced between UEs and HNBs (i.e., one-meter separation). In thedense-urban model, the 3GPP micro-urban model is used for the outdoorpath loss computation of UMTS 30.03 (i.e., Universal MobileTelecommunications System (UMTS), Requirements for the UMTS TerrestrialRadio Access System (UTRA) ETSI Technical Report, UMTS 30.03 version3.1.0, November 1997). The free-space component for the micro-urbanmodel is given by

PL_(fs,micro)(dB)=28+40 log₁₀ d

Other propagation models: Interference management is crucial forenabling Home NodeB (HNB) deployment. At the same time, the conclusionsof any interference management study depend heavily on the underlyingpropagation model. In one aspect, a HNB propagation model is describedthat is useful for studying inter-HNB interference scenarios. In anotheraspect, a HNB-macro propagation model is described for studyingHNB-macro interference issues.

HNB Apartment Building Model: For studying inter-HNB interferencescenarios, the following apartment model is proposed. Consider a 3 floorbuilding with 25 apartments per floor. The apartments are 10 m×10 m andare placed next to each other on a 5×5 grid on each floor. The floorseparation is assumed to be 4 meters. In addition, assume that, withprobability p, there is a HNB in each apartment. This probabilityrepresents the density of HNB deployment. For the apartments that have aHNB, the HNB and HUE are dropped randomly and uniformly in the apartmentwith a minimum separation of one meter. Then a modified version of theKeenan-Motley model is used to calculate the propagation loss from eachHome UE (HUE) to every HNB:

$\begin{matrix}{{{PL}({dB})} = {{20\; {\log_{10}\left( \frac{4\pi \; f}{c} \right)}} + {20\; \log_{10}d} + {q_{i\; n}W_{i\; n}} + {q_{ex}W_{ex}} + {Fn}^{(\frac{({n + 2})}{{({n + 1})} - 0.46})}}} & {{Eqn}.\mspace{14mu} (1)}\end{matrix}$

where

f is the carrier frequency in Hz,

c is the speed of light in m/s,

d is the distance between transmitter and receiver in meters,

W_(in) is the partition loss corresponding to internal walls (e.g.,within an apartment) in dB,

q_(in) is a random variable representing the total number of internalwalls between transmitter and receiver,

W_(ex) is the partition loss representing the total number of internalwalls between transmitter and receiver,

q_(ex) is a random variable representing the total number of externalwalls between transmitter and receiver,

F is the floor loss in dB,

n is number of floors separating transmitter and receiver.

The partition losses, W_(in), W_(ex) and F, are assumed to be fixedwhereas q_(in) and q_(ex) are assumed to be random to capture variationsin apartment layouts. The total number of walls between the transmitterand receiver, q=q_(in)+q_(ex), is a random number chosen from the set

$\left\{ {0,1,\ldots \mspace{14mu},\left\lfloor \frac{d}{d_{w}} \right\rfloor} \right\}$

with equal probability. Here, d_(w) represents the minimum wallseparation. Note that the average distance between two partitions isapproximately equal to 2 d_(w). Given the value of q, the numbers ofinternal and external walls are calculated as follows.q_(in)=q and q_(ex)=0 if the transmitter and receiver are in the sameapartment; and q_(ex)=max(1,└q/k┘) and q_(in)=max(0, q−q_(ex)) if thetransmitter and receiver are in different apartments. Here, k representsthe average number of internal walls per external wall. For ourapartment model k is equal to 10/d_(w). The values suggested for theabove parameters are given in the table below.

TABLE 1 List of parameters for the apartment model. Parameter ValueW_(in) 5 dB W_(ex) 5 dB F 18.3 dB d_(w) 2 m k 5 f 2 × 10⁹ Hz c 3 × 10⁸m/s

HNB-Macro Propagation Model: For studying the interactions between HNBsand Macro NBs (MNBs), the following HNB-macro model is proposed. M HNBhouses (i.e., A HNB house is a house in which there is a HNB) of size 12m×12 m are dropped inside each macrocell. A HNB is dropped randomly anduniformly inside each house. Corresponding to each HNB, a HUE is droppedrandomly such that, with probability p_(HUE), the HUE is inside thehouse and, with probability 1−P_(HUE), the HUE is outside the house inthe yard. The total lot size (including the yard) is assumed to be 24m×24 m. As the HNB houses and HUEs are dropped, the houses are made notoverlap and no HUE is inside a neighbor's house. Then N macro UEs (MUEs)are dropped inside each macrocell. Assume with probability p_(MUE) thatthe MUE is inside a macro house (i.e., macro house is a house in whichthere is no HNB/HUE but there is a MUE) in which case a macro house isdropped for that UE. The macro houses have the same size as the HNBhouses (i.e., 12 m×12 m). The houses are made not overlap and also noHUE is inside a macro house. However, a MUE is not prevented from beinginside a HNB house. In addition, a minimum path loss of X dB is enforcedbetween MUEs and HNBs. In other words, if a MUE is within X dB of a HNBin terms of path loss, the MUE is redropped.

Based on the above model, the various propagation losses are computed asdescribed in the following sections. TABLE 2 summarizes the path losscomputations for various scenarios.

TABLE 2 Summary of path Loss computation for HNB-macro propagationmodel. Cases Path Loss (dB) MUE to MNB MUE is outside 3GPP macrocellmodel described in Annex A of 3GPP TR 25.896 v6.0.0 MUE is inside ahouse PL_(macro)^((v)) + aR + qW + L_(ow)${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{R}{d_{w}} \right\rfloor} \right\}$HUE to MNB HUE is outside 3GPP macrocell model described in Annex A of3GPP TR 25.896 v6.0.0 MUE is inside a housePL_(macro)^((v)) + aR + qW + L_(ow)${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{R}{d_{w}} \right\rfloor} \right\}$MUE to HNB MUE is inside the same house as HNB 37 + 20  log₁₀d + qW${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{d}{d_{w}} \right\rfloor} \right\}$MUE is outsidemax (15.3 + 37.6  log₁₀d, 37 + 20  log₁₀d) + qW + L_(ow)${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{\hat{d}}{d_{w}} \right\rfloor} \right\}$MUE is inside a different housemax (15.3 + 37.6  log₁₀d, 37 + 20  log₁₀d) + qW + L_(ow)⁽¹⁾ + L_(ow)⁽²⁾${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{{\hat{d}}_{1} + {\hat{d}}_{2}}{d_{w}} \right\rfloor} \right\}$HUE to HNB HUE is inside the same house as HNB 37 + 20  log₁₀d + qW${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{d}{d_{w}} \right\rfloor} \right\}$HUE is outsidemax (15.3 + 37.6  log₁₀d, 37 + 20  log₁₀d) + qW + L_(ow)${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{\hat{d}}{d_{w}} \right\rfloor} \right\}$HUE is inside a different housemax (15.3 + 37.6  log₁₀d, 37 + 20  log₁₀d) + qW + L_(ow)⁽¹⁾ + L_(ow)⁽²⁾${{with}\mspace{14mu} q} \in \left\{ {0,1,\ldots \mspace{11mu},\left\lfloor \frac{{\hat{d}}_{1} + {\hat{d}}_{2}}{d_{w}} \right\rfloor} \right\}$

Propagation Loss from MUEs to Macro NodeBs (MNBs): (A) If the MUE isoutside, the macrocell propagation model described in Annex A of 3GPP TR25.896 v6.0.0, “Feasibility Study for Enhanced Uplink for UTRA FDD” isused. (B) If the MUE is inside a house, a model similar to theindoor-outdoor model described in Section 5.2.1 of 3GPP TR 25.951v7.0.0, “FDD Base Station (BS) classification” can be used. Morespecifically, the MUE is projected into four virtual UEs located at theedges of the house. The path loss is then computed as

PL(dB)=PL_(macro(v)) +aR+qW+L _(ow)   Eqn. (2)

where PL^((v)) _(macro) is the path loss from a MNB to the virtual UE, Ris the distance between the MUE and the virtual UE, q is the totalnumber of walls between the MUE and the virtual UE, W is the wallpartition loss which is set to 5 dB, a is the attenuation coefficientequal to 0.8 dB/m, and L_(ow) is the outdoor penetration loss. Similarto the HNB model described in Section 2.1, assume that q is a randomnumber chosen from the set

$\left\{ {0,1,\ldots \mspace{14mu},\left\lfloor \frac{R}{d_{w}} \right\rfloor} \right\}$

with equal probability where d_(w) is again set to 2 m. In addition,assume that L_(ow) is 10 dB with probability 0.8 and is equal to 2 dBwith probability 0.2 to account for windows. The path loss correspondingto each of the four virtual UEs according to Eqn. (2) is calculated, andthe smallest one is chosen.

Propagation Loss from HUEs to MNBs: The propagation loss from a HUE to aMNB can be calculated in the same way as the one just described.

Propagation Loss from MUEs to HNBs: (A) If the MUE is inside the samehouse as the HNB, Eqn. (1) is used to compute the path loss. (B) If theMUE is outside, the path loss is computed as

PL(dB)=PL_(fs) +qW+L _(ow)   Eqn. (3)

where PL_(fs) is the free space loss given by

PL_(fs)(dB)=max(15.3+37.6 log₁₀ d, 37+20 log₁₀ d)   Eqn. (4)

with d being the distance between the MUE and HNB in meters. Here, q isthe total number of walls between the MUE and the HNB, W is the wallpartition loss and L_(ow) is the outdoor penetration loss. In this case,q is a random number chosen from the set

$\left\{ {0,1,\ldots \mspace{14mu},\left\lfloor \frac{\hat{d}}{d_{w}} \right\rfloor} \right\}$

where {circumflex over (d)} is the portion of d inside the house.

(C) If the MUE is inside a different house than the HNB, the path lossis calculated as

PL(dB)=PL_(fs) +qW+L _(ow) ⁽¹⁾ +L _(ow) ⁽²⁾   Eqn. (5)

where PL_(fs) is given by (4), L_(ow) ⁽¹⁾ and L_(ow) ⁽²⁾ are thepenetration losses for the two houses, and q is a random number chosenfrom the set

$\left\{ {0,1,\ldots \mspace{14mu},\left\lfloor \frac{{\hat{d}}_{1} + {\hat{d}}_{2}}{d_{w}} \right\rfloor} \right\}.$

Here, {circumflex over (d)}₁ and {circumflex over (d)}₂ are the portionsof d inside the two houses.

Propagation Loss from HUEs to HNBs: The propagation loss from a HUE to aHNB can be calculated in a similar way as the one just described.

Thus, additional propagation models specific for studying inter-HNB andHNB-macro interference issues have been described.

In plot 800 depicted in FIG. 8, a Cumulative Density Function (CDF) 802of path loss (PL) from mobile user equipment (MUE) to the closest HomeBase Node (HNB) is shown in FIG. 8 for the dense-urban.

Coverage Analysis with Calibrated HNB Transmit Power: One value of HNBtransmit power does not work in all scenarios. Hence, HNB transmit powerneeds to be adapted to provide acceptable performance for HUEs and MUEs.The following algorithm can be used as a guideline to pick the HNB DLtransmit power:

In FIG. 9, a methodology or sequence of operations 900 is depicted foran idle cell reselection procedure for determining whether a HUE iscamped on its HNB or on a MNB or whether it is moved to another carrier.A HUE will be moved to another carrier (block 902) if it is not able toacquire the pilots of the HNB and MNB on the shared carrier (block 904).Similarly, the HUE will be moved to another node (block 904) if the HUEunsuccessfully attempts to perform an idle cell reselection to aneighbor HNB (e.g., restricted association) (block 906). Similarly, aMUE will be moved to another carrier if it is not able to acquire themacro pilot or if it (unsuccessfully) attempts to perform an idle cellreselection to a HNB (not shown). TABLE 3 summarizes representative idlecell reselection parameters used in our analysis. These parameters areset such that priority is given to HNBs over MNBs when a HUE isperforming idle cell reselection (block 908). However, a minimum CPICHEc/No of −19 dB is enforced for HNBs so that idle cell reselection to aHNB happens only when the HNB signal quality is good (block 910).

TABLE 3 Parameters for idle cell reselection procedure. Parameters foridle cell reselection procedure SIB/Parameter Macro HNB SIB3 Qqualmin−18 dB −18 dB Sintrasearch 10 dB 4 dB Sintersearch NA NA SIB11 Qhyst +Qoffset HNB cells: −50 dB HNB cells: 3 dB Macro cells: 3 dB Macro cells:5 dB Qqualmin HNB cells: −12 dB Not needed Macro cells: not needed

In FIG. 10, a methodology or sequence of operations 1000 is provided forHNB transmit power calibration, which can be an algorithm implemented byat least one processor, stored on computer readable storage medium forcausing a computer to execute the method, or components of an apparatus.Each UE performs an idle cell reselection procedure, such as describedabove (block 1002). The transmit power of HNB is determined as follows(block 1003). Each HNB measures the total signal strength (i.e., Noise(No)) from all of the other Base Node (NodeBs, including MNBs and HNBs)(block 1004). It also measures the pilot strength (Ec) from the best MNB(block 1006). Based on these measurements, the HNB determines itstransmit power (block 1008):

Constraint 1: To maintain a CPICH Ec/No of −18 dB for a MUE located X1dB away from the HNB on the same channel (i.e., protect the co-channelmacro user) (block 1010);

Constraint 2: To maintain a CPICH Ec/No of −18 dB for a MUE located X2dB away from the HNB on the adjacent channel (i.e., protect the adjacentchannel macro user) (block 1012);

Constraint 3: To make sure that HNB is not causing unnecessaryinterference to others by enforcing a cap on CPICH Ec/No of the HUE of−15 dB at X3 dB away from the HNB (block 1014).

If HNB uses its own measurements for calibration of its transmit powerthis error could results in lower or higher transmit power valuescompared to optimum. As a practical method to prevent worst caseserrors, certain upper and lower limits on HNB transmit power areenforced (block 1016).

In summary HNB picks the minimum of the values obtained from Constraints1, 2, and 3, and ensures that the value is in the acceptable range(i.e., between Pmin and Pmax) (block 1018).

In this portion, performance of UEs is analyzed with calibrated HNBtransmit power algorithm described above. For the algorithm, setX1=X3=80 dB. The second constraint in the algorithm is not applicablesince assume single-frequency co-channel deployment here. TABLE 4 andTABLE 5 show the pilot acquisition and outage statistics for dense-urbanmodel with calibrated HNB transmit power. Compare two cases:

Calibrated HNB transmit power with Pmin=0 dBm and Pmax=20 dBm;

Calibrated HNB transmit power with Pmin=−10 dBm and Pmax=20 dBm.

TABLE 4 Pilot acquisition statistics for dense-urban model with 24active HNBs and calibrated HNB transmit power Pmin = 0 dBm, Pmin = −10dBm, Pmax = 20 dBm Pmax = 20 dBm HUEs unable to acquire 0.5% 2.0% HNBpilot HUEs unable to acquire 0.2% 0.2% HNB or macro pilot MUEs unable toacquire 13.0% 7.3% macro pilot

TABLE 5 Coverage statistics for dense-urban model with 24 active HNBsand calibrated HNB transmit power. Pmin = 0 dBm, Pmin = −10 dBm, Pmax =20 dBm Pmax = 20 dBm MUEs moved to another 24.0% 14.3% carrier HUEs inHNB outage 2.4% 5.0% HUEs switched to macro 1.1% 3.6% on shared carrierHUEs moved to another 1.3% 1.4% carrier

The HNB transmit power CDFs 1100, 1200 are also shown respectively inFIG. 11 and FIG. 12.

It is seen that in dense-urban model, a significant number of HNBs hitthe minimum −10 dBm transmit power (FIG. 12). Limiting minimum HNB powerto 0 dBm will result in significant coverage hole for the macro. Asshown in TABLE 5, 24% of MUEs will switch to another frequency with 0dBm HNB Tx power compared to 14% with −10 dBm Tx power. This suggeststhat the lower limit for the total HNB Tx power should be set below 0dBm to limit the coverage hole created for the macrocell downlink. Thiswill result in CPICH power levels below the −10 dBm minimum for PrimaryCPICH Tx Power that can currently be signaled to a UE as specified in TS25.331 (i.e., 3GPP TS 25.331 v8.3.0, “Radio Resource Control (RRC);Protocol specification”), as understood by one skilled in the art.

In this disclosure, the impact has been studied of HNB minimum total Txpower level on the coverage hole created for macro downlink performancein a co-channel deployment where HUEs and MUEs share the same carrier.The HNB transmit power has been shown to need to go lower than 0 dB tolimit the coverage hole for macro. This can result in a CPICH Tx powerbelow −10 dBm. The CPICH Tx power is signaled to the UE by RRC and isused by the UE to estimate the path loss to the NodeB. The estimatedpath loss is used by the UE for determining the its initial Tx power forRACH:

Preamble_Initial_Power=Primary CPICH Tx power−CPICH_(—) RSCP+ULinterference+Constant Value

Currently, the lowest CPICH power level that can be signaled to the UEis −10 dBm as specified in 3GPP TS 25.331 v8.3.0, “Radio ResourceControl (RRC); Protocol specification”. When the HNB CPICH Tx power isbelow −10 dBm, the estimated path loss by the HUE (i.e., Primary CPICHTx power−CPICH_RSCP) will be higher than the actual path loss. This willresult in a higher Tx power by the HUE than necessary. The increase inthe HUE Tx power will expedite the access but at same time causesunnecessary interference for the macro uplink. To get around this, theHNB can use the Constant Value parameter to compensate for the mismatchbetween the actual CPICH Tx power level and the one signaled to the HUE.In TS 25.331, the allowed range for the Constant Value parameter isspecified as [−35 dB . . . −10 dB]. The Constant Value signaled to theHUE can be made lower than the desired target to offset the increase inthe estimated path loss resulted from the mismatch in CPICH Tx power

In summary, the HNB total Tx power may need to go below 0 dBm to limitthe coverage hole created for macro downlink. This could result in a HNBCPICH Tx power below −10 dBm which is the lowest level that currentlycan be signaled to the UE and, hence, an error in the path lossestimated by the HUE. However, the mismatch can be compensated byadjusting the Constant Value parameter that is signaled to the HUE bythe HNB for RACH.

By virtue of the foregoing, in one aspect, an apparatus is provided thatis operable in wireless communication system. Means are provided forreceiving a pilot channel signal transmitted at a first power level.Means are provided for receiving an indication that the pilot channelsignal was transmitted at a second power level, wherein the first powerlevel and the second power level are different. Means are provided forreceiving a constant value used in adjusting a preamble initial powervalue. Means are provided for adjusting the preamble initial power valueusing the constant value, the first power level, and the second powerlevel.

In another aspect, a method is provided that is used in wirelesscommunication system. A pilot channel signal is received that istransmitted at a first power level. An indication is received that thepilot channel signal was transmitted at a second power level, whereinthe first power level and the second power level are different. Aconstant value is received used in adjusting a preamble initial powervalue. The preamble initial power value is adjusted using the constantvalue, the first power level, and the second power level. An electronicdevice can be configured to execute this method. An electronic devicecan be provided that is configured to execute the method.

In an additional aspect, a machine-readable medium comprisesinstructions which, when executed by a machine, cause the machine toperform operations including receiving a pilot channel signaltransmitted at a first power level; receiving an indication that thepilot channel signal was transmitted at a second power level, whereinthe first power level and the second power level are different;receiving a constant value used in adjusting a preamble initial powervalue; and adjusting the preamble initial power value using the constantvalue, the first power level, and the second power level.

With reference to FIG. 13, illustrated is a system 1300 for signalingtransmit power outside of a defined range, in particular for signalingon a downlink an uplink transmit power in a closed subscriber system.For example, system 1300 can reside at least partially within userequipment (UE). It is to be appreciated that system 1300 is representedas including functional blocks that represent functions implemented by acomputing platform, processor, software, or combination thereof (e.g.,firmware). System 1300 includes a logical grouping 1302 of electricalcomponents that can act in conjunction. For instance, logical grouping1302 can include an electrical component for determining a targettransmit power level that is desired for the HUE that is outside ofdefined range for a power command by an offset value 1304. Moreover,logical grouping 1302 can include an electrical component fortransmitting a power command to the HUE at a value within the definedrange that is closest to the target uplink transmit power level 1306.Logical grouping 1302 can include an electrical component fortransmitting a mitigation signal to the HUE based upon the offset value1308. Logical grouping 1302 can include an electrical component forreceiving an uplink channel at the target transmit power level, whereinthe HUE adjusts transmit power from the power command according to themitigation signal 1310. Logical grouping 1302 can include an electricalcomponent for determining that an actual transmit power that results inCommon Pilot Channel (CPICH) power outside of a valid range 1312.Logical grouping 1302 can include an electrical component fortransmitting on a downlink a value for CPICH power at a lowest validvalue 1314. Logical grouping 1302 can include an electrical componentfor transmitting a constant value according to the actual transmit power1316. Logical grouping 1302 can include an electrical component forreceiving a Random Access Channel (RACH) preamble from HUE according toan actual path loss based upon the value for CPICH power and theconstant value 1318. Logical grouping 1302 can include an electricalcomponent for transmitting a value for Cell Individual Offset (CIO) toset handover boundaries based upon the actual path loss 1320. Logicalgrouping 1302 can include an electrical component for mitigatinginterference by reducing uplink receiving to an actual sensitivity 1322.Logical grouping 1302 can include an electrical component for adjustinga parameter (e.g., uplink interference, constant values, etc.) to forcethe HUE to transmit RACH preamble at a value corresponding to the actualsensitivity 1324. Logical grouping 1302 can include an electricalcomponent for transmitting the adjusted parameter to the HUE 1326.Logical grouping 1302 can include an electrical component for receivingthe random access channel preamble 1328. Additionally, system 1300 caninclude a memory 1330 that retains instructions for executing functionsassociated with electrical components 1304-1328. While shown as beingexternal to memory 1320, it is to be understood that one or more ofelectrical components 1304-1328 can exist within memory 1330.

In FIG. 14, an apparatus 1402 is depicted for signaling transmit poweroutside of a defined range, in particular for signaling on a downlink anuplink transmit power in a closed subscriber system. Means 1404 areprovided for determining a target transmit power level that is desiredfor the HUE that is outside of defined range for a power command by anoffset value. Means 1406 are provided for transmitting a power commandto the HUE at a value within the defined range that is closest to thetarget uplink transmit power level. Means 1408 are provided fortransmitting a mitigation signal to the HUE based upon the offset value.Means 1410 are provided for receiving an uplink channel at the targettransmit power level, wherein the HUE adjusts transmit power from thepower command according to the mitigation signal. Means 1412 areprovided for determining that an actual transmit power that results inCommon Pilot Channel (CPICH) power outside of a valid range. Means 1414are provided for transmitting on a downlink a value for CPICH power at alowest valid value. Means 1416 are provided for transmitting a constantvalue according to the actual transmit power. Means 1418 are providedfor receiving a Random Access Channel (RACH) preamble from HUE accordingto an actual path loss based upon the value for CPICH power and theconstant value. Means 1420 are provided for transmitting a value forCell Individual Offset (CIO) to set handover boundaries based upon theactual path loss. Means 1422 are provided for mitigating interference byreducing uplink receiving to an actual sensitivity. Means 1424 areprovided for adjusting a parameter (e.g., uplink interference, constantvalues, etc.) to force the HUE to transmit RACH preamble at a valuecorresponding to the actual sensitivity. Means 1426 are provided fortransmitting the adjusted parameter to the HUE. Means 1428 are providedfor receiving the random access channel preamble.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the aspects disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

As used in this application, the terms “component”, “module”, “system”,and the like are intended to refer to a computer-related entity, eitherhardware, a combination of hardware and software, software, or softwarein execution. For example, a component may be, but is not limited tobeing, a process running on a processor, a processor, an object, anexecutable, a thread of execution, a program, and/or a computer. By wayof illustration, both an application running on a server and the servercan be a component. One or more components may reside within a processand/or thread of execution and a component may be localized on onecomputer and/or distributed between two or more computers.

The word “exemplary” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs.

Various aspects will be presented in terms of systems that may include anumber of components, modules, and the like. It is to be understood andappreciated that the various systems may include additional components,modules, etc. and/or may not include all of the components, modules,etc. discussed in connection with the figures. A combination of theseapproaches may also be used. The various aspects disclosed herein can beperformed on electrical devices including devices that utilize touchscreen display technologies and/or mouse-and-keyboard type interfaces.Examples of such devices include computers (desktop and mobile), smartphones, personal digital assistants (PDAs), and other electronic devicesboth wired and wireless.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

Furthermore, the one or more versions may be implemented as a method,apparatus, or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedaspects. The term “article of manufacture” (or alternatively, “computerprogram product”) as used herein is intended to encompass a computerprogram accessible from any computer-readable device, carrier, or media.For example, computer readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips. . . ), optical disks (e.g., compact disk (CD), digital versatile disk(DVD) . . . ), smart cards, and flash memory devices (e.g., card,stick). Additionally it should be appreciated that a carrier wave can beemployed to carry computer-readable electronic data such as those usedin transmitting and receiving electronic mail or in accessing a networksuch as the Internet or a local area network (LAN). Of course, thoseskilled in the art will recognize many modifications may be made to thisconfiguration without departing from the scope of the disclosed aspects.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a user terminal. In the alternative, the processor and thestorage medium may reside as discrete components in a user terminal.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the spirit or scopeof the disclosure. Thus, the present disclosure is not intended to belimited to the embodiments shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

In view of the exemplary systems described supra, methodologies that maybe implemented in accordance with the disclosed subject matter have beendescribed with reference to several flow diagrams. While for purposes ofsimplicity of explanation, the methodologies are shown and described asa series of blocks, it is to be understood and appreciated that theclaimed subject matter is not limited by the order of the blocks, assome blocks may occur in different orders and/or concurrently with otherblocks from what is depicted and described herein. Moreover, not allillustrated blocks may be required to implement the methodologiesdescribed herein. Additionally, it should be further appreciated thatthe methodologies disclosed herein are capable of being stored on anarticle of manufacture to facilitate transporting and transferring suchmethodologies to computers. The term article of manufacture, as usedherein, is intended to encompass a computer program accessible from anycomputer-readable device, carrier, or media.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein, will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

1. A method for signaling on a downlink adjusted parameters toaccurately set a transmit power level for an uplink, comprising:employing a processor executing computer executable instructions storedon a computer readable storage medium to implement following acts:determining a target transmit power level that is desired for a userequipment that is outside of a defined range for a power command by anoffset value; transmitting a power command at a value within the definedrange that is closest to the target transmit power level; transmitting amitigation signal based upon the offset value; and receiving an uplinkchannel at the target transmit power level, wherein the user equipmentadjusts its transmit power from the power command according to themitigation signal.
 2. The method of claim 1, wherein the downlinkchannel comprises a common pilot channel, the method further comprises:determining the target transmit power level that is below the definedrange; transmitting the mitigation signal based upon the offset value bysetting a constant value according to target transmit power level; andreceiving a random access channel preamble according to an actual pathloss.
 3. The method of claim 2, further comprising: transmitting themitigation signal based upon the offset value by setting a value of acell individual offset to ensure that handover boundaries are based uponan actual path loss.
 4. The method of claim 1, further comprising:desensitizing receiving of the uplink channel to mitigate uplinkinterference to an actual sensitivity level that is outside of thedefined range; transmitting the mitigation signal based upon the offsetvalue to force the user equipment to transmit its random access channelpreamble at a transmit power level corresponding to an actualsensitivity level.
 5. The method of claim 1, further comprisingtransmitting the power command and mitigation signal in accordance witha Third Generation Partnership Project (3GPP) telecommunicationstandard.
 6. The method of claim 1, further comprising authenticatingthe user equipment as part of a closed subscriber system.
 7. A computerprogram product for signaling on a downlink adjusted parameters toaccurately set a transmit power level for an uplink, comprising: atleast one computer readable storage medium storing computer executableinstructions that, when executed by at least one processor, implementcomponents comprising: a first set of codes for determining a targettransmit power level that is desired for a user equipment that isoutside of a defined range for a power command by an offset value; asecond set of codes for transmitting a power command at a value withinthe defined range that is closest to the target transmit power level; athird set of codes for transmitting a mitigation signal based upon theoffset value; and a fourth set of codes for receiving an uplink channelat the target transmit power level, wherein the user equipment adjustsits transmit power from the power command according to the mitigationsignal.
 8. An apparatus for signaling on a downlink adjusted parametersto accurately set a transmit power level for an uplink, comprising: atleast one processor; at least one computer readable storage mediumstoring computer executable instructions that, when executed by the atleast one processor, implement components comprising: means fordetermining a target transmit power level that is desired for userequipment that is outside of a defined range for a power command by anoffset value; means for transmitting a power command at a value withinthe defined range that is closest to the target transmit power level;means for transmitting a mitigation signal based upon the offset value;and means for receiving an uplink channel at the target transmit powerlevel, wherein the user equipment adjusts its transmit power from thepower command according to the mitigation signal.
 9. An apparatus forsignaling on a downlink adjusted parameters to accurately set a transmitpower level for an uplink, comprising: a computing platform fordetermining a target transmit power level that is desired for a userequipment that is outside of a defined range for a power command by anoffset value; a transmitter for transmitting a power command at a valuewithin the defined range that is closest to the target transmit powerlevel and for transmitting a mitigation signal based upon the offsetvalue; and a receiver for receiving an uplink channel at the targettransmit power level, wherein the user equipment adjusts its transmitpower from the power command according to the mitigation signal.
 10. Theapparatus of claim 9, wherein the downlink channel comprises a commonpilot channel, the apparatus further comprises, the computing platformis further for determining the target transmit power level that is belowthe defined range; the transmitter is further for transmitting themitigation signal based upon the offset value by setting a constantvalue according to target transmit power level; and the receiver isfurther for receiving a random access channel preamble according to anactual path loss.
 11. The apparatus of claim 10, wherein the transmitteris further for transmitting the mitigation signal based upon the offsetvalue by setting a value of a cell individual offset to ensure thathandover boundaries are based upon an actual path loss.
 12. Theapparatus of claim 9, wherein the computing platform is further fordesensitizing receiving of the uplink channel to mitigate uplinkinterference to an actual sensitivity level that is outside of thedefined range; the transmitter is further for transmitting themitigation signal based upon the offset value to force the userequipment to transmit its random access channel preamble at a transmitpower level corresponding to an actual sensitivity level.
 13. Theapparatus of claim 9, wherein the transmitter is further fortransmitting the power command and mitigation signal in accordance witha Third Generation Partnership Project (3GPP) telecommunicationstandard.
 14. The apparatus of claim 9, wherein the computing platformis further for authenticating the user equipment as part of a closedsubscriber system.
 15. A method comprising: employing a processorexecuting computer executable instructions stored on a computer readablestorage medium to implement following acts: determining that an actualtransmit power that results in common pilot channel power outside of avalid range; transmitting on a downlink a value for common pilot channelpower at a lowest valid value; transmitting a constant value accordingto the actual transmit power; and receiving a random access channelpreamble from user equipment according to an actual path loss based uponthe value for common pilot channel power and the constant value.
 16. Themethod of claim 15, further comprising transmitting a value for cellindividual offset to set handover boundaries based upon the actual pathloss.
 17. The method of claim 15, further comprising signaling inaccordance with a Third Generation Partnership Project (3GPP)telecommunication standard.
 18. The method of claim 15, furthercomprising authenticating the user equipment as part of a closedsubscriber system.
 19. A computer program product comprising: at leastone computer readable storage medium storing computer executableinstructions that, when executed by at least one processor, implementcomponents comprising: a first set of codes for determining that anactual transmit power that results in common pilot channel power outsideof a valid range; a second set of codes for transmitting on a downlink avalue for common pilot channel power at a lowest valid value; a thirdset of codes for transmitting a constant value according to the actualtransmit power; and a fourth set of codes for receiving a random accesschannel preamble from user equipment according to an actual path lossbased upon the value for common pilot channel power and the constantvalue.
 20. An apparatus comprising: at least one processor; at least onecomputer readable storage medium storing computer executableinstructions that, when executed by the at least one processor,implement components comprising: means for determining that an actualtransmit power that results in common pilot channel power outside of avalid range; means for transmitting on a downlink a value for commonpilot channel power at a lowest valid value; means for transmitting aconstant value according to the actual transmit power; and means forreceiving a random access channel preamble from user equipment accordingto an actual path loss based upon the value for common pilot channelpower and the constant value.
 21. An apparatus comprising: a computingplatform for determining that an actual transmit power that results incommon pilot channel power outside of a valid range; a transmitter fortransmitting on a downlink a value for common pilot channel power at alowest valid value and for transmitting a constant value according tothe actual transmit power; and a receiver for receiving a random accesschannel preamble from user equipment according to an actual path lossbased upon the value for common pilot channel power and the constantvalue.
 22. The apparatus of claim 21, wherein the transmitter is furtherfor transmitting a value for cell individual offset to set handoverboundaries based upon the actual path loss.
 23. The apparatus of claim21, wherein the transmitter is further for transmitting in accordancewith a Third Generation Partnership Project (3GPP) telecommunicationstandard.
 24. The apparatus of claim 21, wherein the computing platformis further for authenticating the user equipment as part of a closedsubscriber system.
 25. A method comprising: employing a processorexecuting computer executable instructions stored on a computer readablestorage medium to implement following acts: mitigating interference byreducing uplink receiving to an actual sensitivity; adjusting aparameter to force user equipment to transmit random access channelpreamble at a value corresponding to the actual sensitivity;transmitting the parameter to the user equipment; and receiving therandom access channel preamble.
 26. The method of claim 25, furthercomprising adjusting the parameter of uplink interference.
 27. Themethod of claim 25, further comprising adjusting the parameter ofconstant values.
 28. The method of claim 25, further comprisingtransmitting the parameter in accordance with a Third GenerationPartnership Project (3GPP) telecommunication standard.
 29. A computerprogram product comprising: at least one computer readable storagemedium storing computer executable instructions that, when executed byat least one processor, implement components comprising: a first set ofcodes for mitigating interference by reducing uplink receiving to anactual sensitivity; a second set of codes for adjusting a parameter toforce user equipment to transmit random access channel preamble at avalue corresponding to the actual sensitivity; a third set of codes fortransmitting the parameter to the user equipment; and a fourth set ofcodes for receiving the random access channel preamble.
 30. An apparatuscomprising: at least one processor; at least one computer readablestorage medium storing computer executable instructions that, whenexecuted by the at least one processor, implement components comprising:means for mitigating interference by reducing uplink receiving to anactual sensitivity; means for adjusting a parameter to force userequipment to transmit random access channel preamble at a valuecorresponding to the actual sensitivity; means for transmitting theparameter to the user equipment; and means for receiving the randomaccess channel preamble.
 31. An apparatus comprising: a computingplatform for mitigating interference by reducing uplink receiving to anactual sensitivity and for adjusting a parameter to force user equipmentto transmit random access channel preamble at a value corresponding tothe actual sensitivity; a transmitter for transmitting the parameter tothe user equipment; and a receiver for receiving the random accesschannel preamble.
 32. The apparatus of claim 31, wherein the computingplatform is further for adjusting the parameter of uplink interference.33. The apparatus of claim 31, wherein the computing platform is furtherfor adjusting the parameter of constant values.
 34. The apparatus ofclaim 31, wherein the transmitter is further for transmitting theparameter in accordance with a Third Generation Partnership Project(3GPP) telecommunication standard.